Children experiencing violence. I: Parental use of corporal punishment

OBJECTIVE: This study was undertaken to reveal the prevalence of corporal punishment in Alexandria and its' correlates with family background and child's behavior and characteristics. METHODS: A cross sectional survey targeting preparatory and secondary school children was conducted. The multistage random sample technique was adopted to select a representative sample of this population. Subjects were requested to complete a self-administered questionnaire to collect relevant information. Data were analyzed using the univariate and multivariate analyses. RESULTS: This study revealed that more than one-third (37.47%) of children were disciplined physically in the form of beating and a few were also burned or tied. In 25.83% of them, this harsh discipline led to physical injuries of variable degrees of severity amounting to fractures, loss of consciousness, and permanent disability. Predictive family background for the use of corporal punishment were: living in an apartment shared with strangers; high crowding index; constant fights and quarrels between family members; lack of regular relation with relatives and acquaintance as well as an income insufficient to meet the family basic needs. Predictive child's characteristics and behavior included young age; disobedience; telling lies; destroying others' belongings; acting disrespectfully to parents; communicating poorly with their parents; running away from home; and poor school achievement, in addition to other determinants. CONCLUSION: A proportion of children are subjected to extreme physical brutality amounting to abuse in a disciplinary context. Parents' education and the establishment of effective parent-child communication are deemed essential to combat this phenomenon.     

Polymeric surfactants for enhanced oil recovery. Part I—critical micelle concentration of some ethoxylated alkylphenol—formaldehyde nonionics

Four low molecular weight nonionic polymeric surfactants were prepared by condensing octyl-, dodecyl-, tetradecyl- and hexadecylphenol with para-formaldehyde, and then reacting the resulting resins with ethylene oxide to obtain products with the desired degree of ethoxylation. The molecular weights of the prepared alkylphenol-formaldehyde resins (prior to ethoxylation) were determined by vapour pressure osmometry. The surface tensions of aqueous solutions of these nonionic polymeric surfactants were determined by using the spinning drop method. Plotting the surface tensions obtained versus the logarithm of concentrations resulted in two lines: the pre-CMC (CMC = critical micelle concentration) line (the linear portion below the CMC value) and the post-CMC line (the linear portion above the CMC value). Least squares regression analysis was performed to get the best equation for each of the two lines. Solving these two equations simultaneously resulted in the value of the CMC and the corresponding surface tension (γ_CMC) for each surfactant of the four polymeric nonionic groups. The CMC values obtained for these polymeric surfactants are of the same order of magnitude obtained for monomeric and other polymeric nonionic surfactants.     

Estimation of the reliability function using the delay-time models

The reliability model developed by Christer is used in which the notion of delay-time is involved, which is the span of time from when a defect is first detected upon inspection to when it is considered to have failed. In this paper, a new simplified formula for the reliability function is obtained, in which the delay time and the time to failure densities are exponential distributions. The MLE of the reliability function are also obtained. A numerical procedure is used to solve the results for the new model.     

Book reviews

ENVIRONMENTAL MODELLING FOR DEVELOPING COUNTRIES edited by Asit K. Biswas, T.N. Khoshoo and Ashok Khosla Tycooly Publishing, London and New York, 1990, 166 pp.

COMPUTATIONAL METHODS IN SURFACE HYDROLOGY Edited by G. Gambolati, A. Rinaldo, C.A. Brebbia, W.G. Gray and G.F. Pinder Computational Mechanics Publication, Southampton and Boston. Co‐published with Springer‐Verlag, Berlin, 1990, 556 pp.

GROUNDWATER MONITORING edited by Lorne G. Everett Genium Publication, Schenectady, 1987, 440pp.

WATER POLLUTION IN INDIA by Bharat Desai Lancer Books, New Delhi, 1990, 282pp.     

Spectrum Allocation for Enhanced Cross-Tier Interference Mitigation with Throughput Improvement for Femtocells in a Heterogeneous LTE Cellular Network

Wireless Personal Communications - Femtocells are the solution to improve cellular system capacity in indoor coverage. In two-tier networks, co-channel interference is a serious problem. In this...     

A supply chain model with vendor-managed inventory,consignment, and quality inspection errors

This paper considers the integration between quality control and production inventory control in supply chain management. Specifically, we study the effect of inspection errors on the costs incurred in a supply chain system with a single vendor and multiple buyers. In this system, the vendor enters into a vendor-managed inventory (VMI) and a consignment stock (CS) partnership with several buyers. We assume that the items made by the vendor are not in perfect quality, but they contain a given proportion of defective units. We also assume that quality inspection of these items by the buyers is subject to sampling errors. Three cases indicating to different levels of supply integration are considered: VMI–CS system, traditional system and integrated system. For each case, a mathematical model is formulated, an optimum solution is developed, and a numerical example is solved.     

Real-time scene background initialization based on spatio-temporal neighborhood exploration

In this paper, we address the problem of scene background initialization to define a background model free from foreground objects. The complexity of this task resides in the continuous clutter of the scene by moving and stationary objects. To face this challenge, we propose a robust real-time iterative model completion method based on online block-level processing to initialize the background with low computational cost. First, temporal data analysis is conducted to cluster similar blocks. Meanwhile, a two-folded inter-block spatial neighborhood exploration is performed. It aims to capture relationships among neighboring clusters and reduce the number of candidate clusters employed in the next phase. Then, a smoothness analysis between neighboring locations is performed to iteratively reconstruct the background based on a newly proposed edge matching metric and an inter-block color discontinuity. Extensive evaluations of the proposed approach on the public Scene Background Initialization 2015 dataset and on the Scene Background Modeling Contest 2016 dataset revealed a performance superior or comparable to state-of-the-art methods.

     

Efficient selective image encryption

Multimedia Tools and Applications - Selective image encryption has a significant importance in many applications as it offers significant savings in computations, cost, and time. Many attempts are...     

On the utility of MIMO multi-relay networks for modulation identification over spatially-correlated channels

The necessity to perfectly monitor the intercepted signals for spatially-correlated multiple-input multiple-output (MIMO) systems, involves modulation identification algorithms. In this paper, we present an algorithm dedicated to the modulation identification for correlated MIMO relaying broadcast channels with direct link using multi-relay nodes. By modeling spatially-correlated MIMO channels as Kronecker-structured and the imperfect channel state information of both the source-to-destination and the relay-to-destination errors as independent complex Gaussian random variables, we firstly derive the ergodic capacity of the proposed transmission system. It turns out that the ergodic capacities improve with the number of relay nodes. Based on a pattern recognition approach using the higher order statistics features and the Bagging classifier, we show that the probability to distinguish among M-ary shift keying linear modulation types without any priori modulation information is enhanced compared to the decision tree (J48), the tree augmented naive Bayes, the naive Bayes using discretization and the multilayer perceptron classifiers. We also study the effect of increasing the number of relay nodes. Numerical simulations show that the proposed algorithm using the cooperation of multi-relay nodes with the source node can avoid the performance deterioration in modulation identification caused by both spatial correlation and imperfect CSI.     

A parametric study of the heat absorption capacity of metallic moulds-fundamental patterns of its time variation

The capacity of a metallic mould to absorb heat from the solidifying casting plays a key role in controlling the metallurgical, technological and mechanical properties of the casting. Therefore, the main objective of the present paper is to reveal the nature of the mould cooling capacity-time history and to establish a map for the fundamental patterns of this relationship. The extent of the mutual interactions among the principal variables is also examined. The analysis of the present work is confined to a spherical mould of uniform wall thickness to simulate a unidirectional heat flow. The solution of the problem is obtained through finite element approximation. An approximate analytical solution, based on the heat balance integral method, is developed to extend the fundamental solution obtained in this study to the case of transient boundary condition. Application of this analytical development is demonstrated using experimental data. Analysis of the results indicated that the time variation of the mould cooling capacity follows one of two distinctive patterns depending on the combination of govering variables. An unexpected behaviour has been observed; the negative effect of Biot modulus under conditions of no preheat. The effects of various governing variables on the mould cooling capacity have been discussed and summarised.